package com.biluo.yygh.gateway.filter;

import com.alibaba.fastjson.JSONObject;
import com.biluo.yygh.common.helper.JwtHelper;
import com.biluo.yygh.common.result.Result;
import com.biluo.yygh.common.result.ResultCodeEnum;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.List;

/**
 * <p>
 * 全局Filter，统一处理会员登录与外部不允许访问的服务
 * </p>
 *
 * @author qy
 * @since 2019-11-21
 */
@Component
public class AuthGlobalFilter implements GlobalFilter, Ordered {

	private final AntPathMatcher antPathMatcher = new AntPathMatcher();

	@Override
	public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
		ServerHttpRequest request = exchange.getRequest();
		String path = request.getURI().getPath();
		System.out.println("===" + path);

		// 内部服务接口，不允许外部访问
		if (antPathMatcher.match("/**/inner/**", path)) {
			ServerHttpResponse response = exchange.getResponse();
			return out(response, ResultCodeEnum.PERMISSION);
		}

		// api接口，异步请求，校验用户必须登录
		if (antPathMatcher.match("/api/**/auth/**", path)) {
			Long userId = this.getUserId(request);
			if (StringUtils.isEmpty(userId)) {
				ServerHttpResponse response = exchange.getResponse();
				return out(response, ResultCodeEnum.LOGIN_AUTH);
			}
		}
		return chain.filter(exchange);
	}

	@Override
	public int getOrder() {
		return 0;
	}

	/**
	 * api接口鉴权失败返回数据
	 *
	 * @param response
	 * @return
	 */
	private Mono<Void> out(ServerHttpResponse response, ResultCodeEnum resultCodeEnum) {
		Result result = Result.build(null, resultCodeEnum);
		byte[] bits = JSONObject.toJSONString(result).getBytes(StandardCharsets.UTF_8);
		DataBuffer buffer = response.bufferFactory().wrap(bits);
		// 指定编码，否则在浏览器中会中文乱码
		response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");
		return response.writeWith(Mono.just(buffer));
	}

	/**
	 * 获取当前登录用户id
	 *
	 * @param request
	 * @return
	 */
	private Long getUserId(ServerHttpRequest request) {
		String token = "";
		List<String> tokenList = request.getHeaders().get("token");
		if (null != tokenList) {
			token = tokenList.get(0);
		}
		if (!StringUtils.isEmpty(token)) {
			return JwtHelper.getUserId(token);
		}
		return null;
	}
}
